JP2012001367A - Sheet processing device and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet processing device capable of solving such a problem that productivity is deteriorated and a cost increase occurs and the accuracy of sheet position control is impaired, and to provide an image forming device.SOLUTION: A finisher control part controls the position of a sheet stopper 805 so that a position on a sheet bundle P to be stapled by a stapler 820 is previously shifted a shift amount (α) to the opposite face side to one face of the folded sheet bundle P to be guided by an upper side guide 814a for stapling processing. Thus, end processing can be applied in a state of keeping staples in their proper positions while actualizing such an inexpensive configuration that a conveyance passage for delivering the sheet bundle to be folded and conveyed from a first folding roller pair 810 to a fold pressing unit is curved to suppress an increase in the width of the device. This solves such a problem that final products are deteriorated.

Description

  The present invention relates to a sheet processing apparatus that processes a sheet and an image forming apparatus including the sheet processing apparatus.

  2. Description of the Related Art Conventionally, as an image forming apparatus for forming an image on a sheet, a sheet processing apparatus having a configuration in which a sheet formed with an image on a main body is bundled and then folded into two to form a booklet is used. Are known. Hereinafter, this booklet is referred to as saddle stitch bookbinding, and a device that performs saddle stitch bookbinding processing is referred to as a saddle stitch bookbinding apparatus. In such a sheet processing apparatus, after sheets are sequentially received by a tray, they are aligned in a bundle and stapled near the center in the conveyance direction. Then, the staple binding portion is projected by a protruding member and pushed into a nip of a pair of folding rollers, and is folded while the sheet bundle is conveyed by the pair of folding rollers. (See Patent Document 1)

  The operation of such a conventional sheet processing apparatus will be described with reference to FIGS. 2, 16, 17, and 18. FIG. Note that FIG. 2 will be described by extracting only parts necessary for the description of the prior art.

  As shown in FIG. 2, the finisher (sheet processing apparatus) 500 first receives and aligns a plurality of sheets conveyed to the storage guide 803 sequentially by a sheet stopper 805, and then uses a stapler 820 to center the conveyance direction. Stitches. Subsequently, the protruding member 830 protrudes the staple binding portion of the sheet bundle and pushes it into the nip of the first folding roller pair 810a, 810b. The first folding roller pair 810a, 810b bends the sheet bundle while conveying it, and sequentially conveys the sheet bundle to the second folding roller pair 811a, 811b and the third folding roller pair 812a, 812b.

  Thereafter, the sheet conveyance is temporarily stopped when the folded end portion of the folded sheet bundle is conveyed to the processing position of the additional folding roller pair 861. Then, the additional folding roller pair 861 moves in the width direction perpendicular to the sheet conveying direction along the sheet crease, and performs the strengthening process of the folded portion (see FIG. 16). Thereafter, the folded sheet bundle is conveyed and discharged to the folded bundle tray 840.

  In the conventional finisher, both the sheet stapling process and the folding process are controlled so that the process is performed at the center of the sheet. That is, when the sheets are stacked, the sheets P are sequentially stacked on the sheet stopper 805 waiting at a half of the conveyance direction length L of the sheet bundle P, that is, on the lower side of L / 2 around the staple binding position of the stapler 820. Thereafter, a stapling process by the stapler 820 is performed.

  Thereafter, the sheet bundle P and the sheet are separated by a distance L1 from the center of the stapler 820 to the center of the nip of the first folding roller pair 810 so that the center of the nip of the first folding roller pair 810 and the staple binding portion of the sheet P coincide with each other. The stopper 805 moves together (see FIG. 16).

  By the way, for example, to reduce the apparatus width, the first folding roller pair 810, the second folding roller pair 811 and the third folding roller pair 812 are not arranged linearly but are shown in FIGS. In some cases, the conveyance path is curved as described above. That is, the second folding roller pair 811 is positioned slightly above the first folding roller pair 810, and the third folding roller pair 812 is positioned below the first and second folding roller pairs 810 and 811. The nip direction of the two-fold roller pair 811 faces the lower left side. Overall, the nip of the additional folding roller pair 861 is located on the lower side in FIG. 18 with respect to the nip of the first folding roller pair 810.

JP 2007-076793 A

  However, when the sheet bundle P that has been subjected to the stapling process and the folding process at the center is conveyed through the bent conveyance path, the following occurs. That is, the front end of the sheet bundle is directed downward by the upper guide 814a of the upper and lower guides 814a and 814b of the conveyance guide portion 814 between the folding roller pair 811 and 812. As a result, the sheet bundle P is in a state in which the outer side (upper side) is stretched due to the conveyance resistance from the upper guide 814a, and the inner side (lower side) is in a state of sagging.

  When a state where the sheet bundle P is stretched and a state where the sheet bundle P sag is generated as described above, the staples S originally applied in parallel to the sheet bundle P are directed upward.

  Subsequently, the sheet bundle P is conveyed to the third folding roller pair 812, and as shown in FIG. 17, the portions of the additional folding roller pair 861 and the crushing roller pair 862 with the staple staple S facing upward. And then paused.

  As shown in FIG. 18 which is a plan view, the sheet bundle P is conveyed to the position of the additional folding roller pair 861 and the crushing roller pair 862 at a position shifted in the longitudinal direction of the apparatus (front-back direction in FIG. 2). , Paused. Thereafter, the additional folding roller pair 861 and the crushing roller pair 862 move in the direction of arrow a in FIG. 18, and the additional folding process and the crushing process are performed on the folding leading end portion (near the staple needle S) of the sheet bundle P. The additional folding roller pair 861 is configured such that a force is applied in the direction of the arrow Fp shown in FIG. 17 and can swing in the direction of the arrow Rp in FIG. Further, the crushing roller pair 862 is configured so that a force is applied in the direction of arrow Ft in FIG. 17 and can swing in the direction of arrow Rt.

  In the conventional finisher as described above, since the additional folding and crushing operations are performed with the staple needle S facing upward as described above, the final product is finally the staple needle S facing upward. The quality of the half-folded sheet bundle P is impaired. That is, when the sheet bundle is conveyed through the curved conveyance path, the folding leading end portion of the sheet bundle is deformed, and the staple needle S is displaced from the center, and further folding and crushing processing is performed, the staple needle S is displaced. It will be the final product that has lost its quality.

  SUMMARY OF THE INVENTION Accordingly, the present invention provides a sheet processing apparatus capable of solving problems such as a decrease in productivity and a cost increase, and a problem of impairing the accuracy of sheet position control, and an image forming apparatus including the sheet processing apparatus. With the goal.

  The present invention provides a sheet stacking unit that sequentially stacks conveyed sheets, and a positioning member that abuts an end of the sheet transported to the sheet stacking unit for positioning a sheet bundle stacked on the sheet stacking unit. And a staple binding processing unit that performs a staple binding process on the sheet bundle stacked on the sheet stacking unit, and the positioning member is moved to adjust the staple binding position on the sheet bundle by the staple binding processing unit. A folding processing unit that folds the sheet bundle that has been stapled by the staple binding processing unit, and one side of the folded sheet bundle that is conveyed from the folding processing unit with the folding end as the head. A conveying guide member that guides the folded sheet bundle while slidingly contacting the sheet, an end processing unit that performs end processing with respect to a folded end portion of the folded sheet bundle guided by the conveying guide member, and an end processing unit Department When the sheet binding is performed, the staple binding position is moved by a predetermined distance in advance to a region opposite to the region that becomes the one surface when the sheet bundle stacked on the sheet stacking unit is folded in half. A control unit for controlling movement of the positioning member so as to perform processing.

  According to the present invention, one surface of the folded sheet bundle fed out from the folding processing unit with the folded end as the head comes into sliding contact, and the end processing can be performed without impairing the quality of the final product. By the conveyance guide member that curves and guides the folded sheet bundle, it is possible to reduce the size of the apparatus while suppressing an increase in the apparatus width. In addition, by performing the edge processing in a state where the staple position is appropriate in consideration of the resistance of the conveyance guide member, it is possible to realize a sheet processing apparatus that does not impair the quality of the final product.

1 is a cross-sectional view illustrating a copying machine as an example of an image forming apparatus including a finisher that is a sheet processing apparatus according to an embodiment of the present invention. Sectional drawing which shows the finisher which concerns on 1st Embodiment. The block diagram which shows the finisher which concerns on 1st Embodiment. Operation | movement explanatory drawing of the finisher which concerns on 1st Embodiment. Operation | movement explanatory drawing of the finisher which concerns on 1st Embodiment. Operation | movement explanatory drawing of the finisher which concerns on 1st Embodiment. Operation | movement explanatory drawing of the finisher which concerns on 1st Embodiment. (A), (b) is operation | movement explanatory drawing of the finisher which concerns on 1st Embodiment. (A), (b) is operation | movement explanatory drawing of the finisher which concerns on 1st Embodiment. Operation | movement explanatory drawing of the finisher which concerns on 1st Embodiment. Operation | movement explanatory drawing of the finisher which concerns on 1st Embodiment. FIG. 2 is a control block diagram of the copying machine according to the first embodiment. FIG. 3 is a control block diagram of the finisher according to the first embodiment. FIG. 6 is a flowchart showing the operation of the finisher according to the first embodiment. (A), (b) is operation | movement explanatory drawing of the finisher which concerns on 2nd Embodiment to which this invention is applied. FIG. 6 is a diagram illustrating the operation of a conventional finisher. FIG. 6 is a diagram illustrating the operation of a conventional finisher. FIG. 6 is a diagram illustrating the operation of a conventional finisher.

<First Embodiment>
Embodiments according to the present invention will be described below in detail with reference to the drawings. 1 is a cross-sectional view showing a copying machine as an example of an image forming apparatus provided with a finisher as a sheet processing apparatus according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view showing the finisher according to the first embodiment. It is.

(Image forming device)
As shown in FIG. 1, a copying machine 1000 as an image forming apparatus includes a document feeding unit 100, an image reader unit 200, a printer unit 300, a folding processing unit 400, a finisher 500 that is a sheet processing device, and a sheet insertion unit. The inserter 900 is provided. Note that the folding processing unit 400 and the inserter 900 can be optionally provided.

  On the tray 100a of the document feeder 100, the document D is set in a face-up state (the surface on which the image is formed faces up). It is assumed that the staple binding position of the document is the left end portion of the document. Documents set on the tray 100a are conveyed by the document feeding unit 100 one by one from the top page in the left direction, that is, with the staple binding position at the top. Then, the document passes through a curved path and is conveyed from the left to the right on the platen glass 102 and then discharged onto the discharge tray 112. At this time, the scanner unit 104 is stopped at a predetermined document reading position.

  The scanner unit 104 reads an image of a document that passes from the left to the right on the scanner unit 104. When the document passes over the platen glass 102, the document is irradiated by the lamp 103 of the scanner unit 104. The reflected light from the original is guided to the image sensor 109 via the mirrors 105, 106, 107 and the lens 108.

  The document image data read by the image sensor 109 is subjected to predetermined image processing and sent to the exposure control unit 110. The exposure control unit 110 outputs laser light corresponding to the image signal. The laser light is irradiated onto the photosensitive drum 111 while being scanned by the polygon mirror 110a. An electrostatic latent image corresponding to the scanned laser beam is formed on the photosensitive drum 111.

  The electrostatic latent image formed on the photosensitive drum 111 is developed by the developing device 113 and visualized as a toner image. On the other hand, the sheet P is conveyed to the transfer unit 116 from any of the cassettes 114 and 115, the manual feeding unit 125, and the double-sided conveyance path 124. Then, the visualized toner image is transferred to the sheet P in the transfer unit 116. The transferred sheet P is fixed with a toner image by a fixing unit 177. The photosensitive drum 111, the developing device 113, and the like constitute an image forming unit that forms an image on a sheet.

  The sheet that has passed through the fixing unit 177 is once guided to the path 122 by the switching member 121. When the trailing end of the sheet P passes through the switching member 121, the sheet P is conveyed in a switchback and guided to the discharge roller 118 by the switching member 121. The sheet is discharged from the printer unit 300 by the discharge roller 118. As a result, the sheet P is discharged from the printer unit 300 with the surface on which the toner image is formed facing downward (face down). These operations are called “reverse discharge”.

  When the sheet P is discharged to the outside in the face-down state, the image forming process can be performed in order from the first page. For example, the page order can be aligned when image forming processing is performed using the document feeder 100 or when image forming processing is performed on image data from the computer 204 (see FIG. 12).

  When forming images on both sides of the sheet P, the printer unit 300 guides the sheet straight from the fixing unit 177 to the discharge roller 118. Immediately after the trailing edge of the sheet passes through the switching member 121, the sheet P is conveyed in a switchback manner and is guided to the duplex conveyance path 124 by the switching member 121.

(Folding processing unit 400)
The folding processing unit 400 includes a conveyance path 131 for introducing the sheet P discharged from the printer unit 300 and guiding the sheet P to the finisher 500 side. On the conveyance path 131, conveyance roller pairs 130 and 133 are provided. It has been. Further, a switching member 135 is provided in the vicinity of the conveying roller pair 133, and this switching member 135 is for guiding the sheet P conveyed by the conveying roller pair 130 to the folding path 136 or the finisher 500 side. .

  Here, when the folding process is performed on the sheet P, the switching member 135 is switched to the folding path 136 and the sheet P is guided to the folding path 136. Thereafter, the leading edge of the sheet P guided to the folding path 136 is abutted against the stopper 137, and the loop formed gradually by the abutting of the leading edge in this way is folded by the folding rollers 140 and 141. Further, the sheet P is Z-folded by further folding the loop formed by abutting the bent portion against the upper stopper 143 by the folding rollers 141 and 142.

  The Z-folded sheet P is sent to the conveyance path 131 via the conveyance path 145 and is discharged to the finisher 500 on the downstream side by the conveyance roller pair 133. On the other hand, when the folding process is not performed, the switching member 135 is switched to the finisher side, and the sheet P discharged from the printer unit 300 is sent directly to the finisher 500 via the conveyance path 131.

(Finisher 500)
The finisher 500 constitutes a sheet processing apparatus that binds and binds a bundle of sheets on which images have been formed by the image forming unit. The finisher 500 staples the rear end side of the sheet bundle P (stitching process), Bookbinding processing is performed. The finisher 500 is integrally provided with a staple unit 600 that staples sheets and a saddle stitch bookbinding unit 800 that performs bookbinding processing by folding a sheet bundle into two as a sheet stacking device. The finisher 500 aligns a plurality of sheets P conveyed from the printer unit 300 via the folding processing unit 400 and processes the sheets. This sheet processing includes processing for bundling as one sheet bundle P, stapling processing for stapling the sheet bundle P (stitch binding processing), sorting processing, non-sorting processing, and the like.

  As shown in FIG. 2, the finisher 500 has a conveyance path 520 for taking the sheet P conveyed through the folding processing unit 400 into the apparatus. The conveyance path 520 is provided with conveyance roller pairs 502 to 508 in order from the inlet roller pair 501 toward the downstream side in the sheet conveyance direction.

  A punch unit 530 is provided between the conveyance roller pair 502 and the conveyance roller pair 503. The punch unit 530 is configured to perform an operation as necessary, and to make a hole (perforate processing) at the rear end of the conveyed sheet.

  A switching member 513 provided at the end of the transport path 520 switches the path between an upper discharge path 521 and a lower discharge path 522 connected downstream. The upper discharge path 521 guides the sheet to the sample tray 701 by the upper discharge roller 509. On the other hand, the lower discharge path 522 is provided with conveyance roller pairs 510, 511, and 512. These conveyance roller pairs 510, 511, and 512 convey the sheet to the processing tray 550 and discharge it.

  The sheets P discharged to the processing tray 550 are stacked in a bundle while being sequentially aligned, and sorting processing and stapling processing are performed according to settings from the operation unit 1 (see FIG. 12). The processed sheet bundle P is selectively discharged to the stack tray 700 and the sample tray 701 by the bundle discharge roller pair 551.

  The stapling process is performed by the stapler 560. The stapler 560 moves in the sheet width direction (a direction orthogonal to the sheet conveyance direction) and staples an arbitrary portion of the sheet bundle P. The stack tray 700 and the sample tray 701 are moved up and down along the main body of the finisher 500. The upper sample tray 701 receives sheets from the upper discharge path 521 and the processing tray 550. In addition, the lower stack tray 700 receives sheets from the processing tray 550. As described above, a large number of sheets are stacked on the stack tray 700 and the sample tray 701. The stacked sheets are aligned with their rear ends being received by a rear end guide 710 extending in the vertical direction.

  On the other hand, when the switching member 514 provided in the middle of the lower discharge path 522 is switched to the broken line position, the sheet passes through the saddle discharge path 523 and is sent to the saddle stitch bookbinding section 800. In this case, the sheet is first delivered to the saddle entrance roller pair 801, the entrance is selected by the switching member 802 operated by a solenoid according to the size, and is carried into the storage guide 803 of the saddle stitch binding unit 800. . The storage guide 803 forms a sheet stacking unit that sequentially stacks the conveyed sheets.

  The sheet thus carried into the storage guide 803 is conveyed by the intermediate roller 804 until the leading end hits a sheet stopper 805 that can move in the vertical direction. The sheet stopper 805 constitutes a positioning member for positioning the sheet bundle stacked on the storage guide 803, and is movable to adjust the staple binding position on the sheet bundle by the stapler (needle binding processing unit) 820. . The saddle entrance roller pair 801 and the intermediate roller 804 are driven by a motor M1.

  In addition, a stapler 820 including a driver 820 a that is opposed to the storage guide 803 and protrudes a staple needle and an anvil 820 b that bends the protruded needle is disposed in the middle of the storage guide 803. The stapler 820 forms a staple binding processing unit that performs a staple binding process on a sheet bundle stacked on a storage guide 803 that is a sheet stacking unit.

  Here, the sheet stopper 805 is controlled to stop at the position where the central portion in the sheet conveyance direction becomes the staple binding position of the stapler 820 when the sheet is carried. Note that the sheet stopper 805 is movable in the vertical direction under the driving of the motor M2, and the position can be changed according to the sheet size.

  On the downstream side of the stapler 820, a first folding roller pair 810 (810a, 810b) that is a pair of folding rollers that sandwich the sheet bundle and fold it in half is provided. At a position facing the nip of the first folding roller pair 810, a protruding member 830 that pushes the sheet bundle stacked on the storage guide 803 into the first folding roller pair 810 is provided. The first folding roller pair 810 and the protruding member 830 have a folding processing unit that performs a folding process so that the staple binding position of the sheet bundle stapled by the stapler 820 is the folding leading end (folding end). It is composed. Further, the protruding member 830 has a position retracted from the storage guide 803 as a home position, and is driven toward the stored sheet bundle P by driving the motor M3, so that the sheet bundle enters the nip of the first folding roller pair 810. It is configured to push in.

  As the protruding member 830 protrudes toward the sheet bundle in this way, the sheet bundle can be pushed into the nip of the pair of folding rollers 810a and 810b serving as the folding processing unit, whereby the sheet bundle can be folded. . The protruding member 830 is configured to return to the home position again after the sheet bundle is pushed in.

  On the other hand, between the first folding roller pair 810a and 810b into which the sheet bundle is pushed, a pressure sufficient to crease the sheet bundle is applied by a spring (not shown), whereby the folding roller pair 810a and 810b. When passing through the sheet bundle, the sheet bundle is creased. The sheet bundle thus creased is then discharged to the folding bundle tray 840 via the second folding roller pair 811a, 811b, the third folding roller pair 812a, 812b, and the like.

  The second folding roller pair 811a and 811b and the third folding roller pair 812a and 812b are also applied with sufficient pressure to convey and stop the folded sheet bundle. Further, the first folding roller pair 810a and 810b, the second folding roller pair 811a and 811b, and the third folding roller pair 812a and 812b, which are folding processing units, are rotated at the same speed by the same motor M4.

  In FIG. 2, reference numeral 613 denotes a conveyance guide that connects between the first folding roller pair 810a, 810b and the second folding roller pair 811a, 811b. Reference numeral 814 denotes a conveyance guide unit including an upper guide 814a and a lower guide 814b that connect the second folding roller pair 811a and 811b and the third folding roller pair 812a and 812b. The upper guide 814a is configured to bend the folded sheet bundle P by sliding one surface of the folded sheet bundle P fed out from the folding processing section including the first folding roller pair 810 and the protruding member 830 with the folded end as the head. The conveyance guide member which guides is constituted. Note that reference numeral 809 in FIG. 3 denotes a conveyance guide unit, and the conveyance guide unit 809 includes second and third folding roller pairs 811 and 812 arranged in a curved state from the first folding roller pair 810.

  Further, reference numeral 815 in FIG. 2 is an alignment plate pair that has a surface protruding from the storage guide 803 around the outer peripheral surface of the first folding roller pair 810a, 810b and aligns the sheets stored in the storage guide 803. The alignment plate pair 815 is positioned in the width direction of the sheet by being driven by the motor M5 and moving in the nipping direction with respect to the sheet.

  A crease press unit 860 is provided downstream of the third fold roller pair 812a and 812b to reinforce the fold of the sheet bundle. The crease press unit 860 includes an end processing unit that performs end processing (folding processing) on a folded front end (folded end) of the folded sheet bundle (P) guided by the upper guide 814a that is a conveyance guide member. Is configured. The crease press unit 860 as an end processing unit has an additional folding roller pair 861 and a crushing roller pair 862, and is driven by a motor M6 for driving the crease press unit.

  As described above, after the protruding member 830 protrudes upward from the stacking surface side of the storage guide 803 and the sheet bundle pushed into the nip of the first folding roller pair 810 is creased by the crease press unit 860, The paper is discharged to the folding tray 840 downward. By discharging the sheet bundle downward, it is possible to discharge the sheet while maintaining a stable posture, and good stackability can be obtained. With the conveyance guide portion 814 constituting such a curved path, it is possible to satisfactorily stack the sheet bundle that has been subjected to the folding processing and the edge processing while realizing downsizing of the apparatus.

  Here, the control system in this embodiment will be described with reference to FIGS. 12 and 13. FIG. 12 is a control block diagram of the copying machine 1000 in the present embodiment, and FIG. 13 is a control block diagram of the finisher 500 in the present embodiment.

  The CPU circuit unit 150 includes a document feeding control unit 101, an image reader control unit 201, an image signal control unit 202, a printer control unit 301, and a folding processing control unit 401 according to the control program stored in the ROM 151 and the setting of the operation unit 1. To control. Further, the CPU circuit unit 150 controls the finisher control unit 515 and the external I / F 203 in accordance with the control program stored in the ROM 151 and the setting of the operation unit 1.

  The document feeding control unit 101 controls the document feeding unit 100, the image reader control unit 201 controls the image reader unit 200, the printer control unit 301 controls the printer unit 300, and the folding processing control unit 401 controls the folding processing unit 400. . The finisher control unit 515 controls the operations of the staple unit 600, the saddle stitch bookbinding unit 800, the inserter 900, and the like in the finisher 500.

  The finisher control unit 515 constitutes a control unit that controls the movement of the sheet stopper 805 when performing staple binding processing by the stapler 820. This control unit places the staple binding position on the sheet bundle by the stapler 820 on the opposite side (lower side in FIG. 8) from the region that becomes one side (upper side in FIG. 8) when the sheet bundle is folded in half. The position of the sheet stopper 805 is controlled so as to move in advance a predetermined distance and perform the staple binding process. The one surface is guided by the upper guide 814a. This predetermined distance means a shift amount α with respect to the bending processing position.

  In this embodiment, the shift amount α, which is a predetermined distance, is set according to the number of sheet bundles P stacked on the storage guide 803. Further, the shift amount α, which is a predetermined distance, may be set according to the thickness of the sheets of the sheet bundle P stacked on the storage guide 803. Further, instead of these, the shift amount α can be arbitrarily set by an operation of the operation unit 1 by a user (operator) or the like. In these cases, when the edge processing is performed by the crease press unit 860, the position of the staple S at the folding front end (folded end) of the sheet bundle becomes more appropriate according to the type of sheet to be imaged. Can be.

  The operation unit 1 includes a plurality of keys for setting various functions relating to image formation, a display unit for displaying a setting state, and the like. Then, a key signal corresponding to each key operation by the user is output to the CPU circuit unit 150, and corresponding information is displayed on a display unit (not shown) based on the signal from the CPU circuit unit 150.

  The RAM 152 is used as an area for temporarily storing control data and a work area for operations associated with control. An external I / F 203 is an interface between the copying machine 1000 and an external computer 204, develops print data from the computer 204 into a bitmap image, and outputs it to the image signal control unit 202 as image data.

  Further, an image of a document read by an image sensor (not shown) is output from the image reader control unit 201 to the image signal control unit 202, and the printer control unit 301 receives image data from the image signal control unit 202 (not shown). Output to the exposure controller.

  Further, as shown in FIG. 13, the finisher control unit 515 sends signals from the inlet sensor 62, the sheet stopper position detection sensor 44, the bundle conveyance position detection sensor 51, and the additional folding member position detection sensor 63 via the input interface 57. Receive each. The entrance sensor 62 detects the sheet conveyed to the entrance roller pair 501, and the sheet stopper position detection sensor 44 detects the position of the sheet stopper 805. The bundle conveyance position detection sensor 51 (see FIG. 9A) detects the position of the sheet bundle P, and the additional folding member position detection sensor 63 detects the position of the additional folding roller pair 861 and the like.

  The finisher control unit 515 controls driving of the motors M <b> 1 to M <b> 6 via the output interface 58 according to the control program stored in the ROM 59. Further, the RAM 61 connected to the finisher control unit 515 is used as an area for temporarily holding control data and a work area for operations associated with control.

  The motor M1 drives the saddle entrance roller pair 801 and the intermediate roller 804, and the motor M2 moves the sheet stopper 805 in the vertical direction. The motor M3 operates the protruding member 830 so as to protrude toward the stored sheet bundle P from the home position retracted from the storage guide 803. The motor M4 drives the first folding roller pair 810, the second folding roller pair 811, and the third folding roller pair 812 at a constant speed. The motor M5 moves the alignment plate pair 815 in the sandwiching direction with respect to the sheet, thereby positioning the sheet in the width direction. The motor M6 drives the crease press unit 860 having the crease roller unit 861 and the crush roller pair 862.

(Saddle Stitch Binding 800)
Next, an outline of the configuration and operation of the saddle stitch bookbinding unit 800 as a sheet stacking apparatus will be described with reference to the flowcharts of FIGS. FIG. 4 is an enlarged view of the stapler 820 portion of FIG.

  In the following description, the process of bending the sheet bundle P by the first folding roller pair 810 (810a, 810b) and the protruding member 830 is referred to as a bending process. Further, for the sheet bundle P that has been subjected to the folding process, a process for strengthening the crease with the additional folding roller pair 861 is referred to as an additional folding process. In addition, a process of crushing the sheet bundle P that has been subjected to the folding process by crushing the front end of the sheet folding processing portion (the folding front end portion of the sheet bundle) with the crushing roller pair 862 is referred to as a crushing process. The operations of the additional folding process and the crushing process are the same as those described above with reference to FIG. The additional folding roller pair 861 is configured such that a force is applied in the direction of the arrow Fp shown in FIG. 11 and can swing in the direction of the arrow Rp in FIG. Further, the crushing roller pair 862 is configured such that a force is applied in the direction of the arrow Ft in FIG. 11 and can swing in the direction of the arrow Rt.

  In the present embodiment, the saddle stitch bookbinding unit 800 is incorporated in the finisher 500 as a device having the above processing functions. First, the finisher 500 receives information on the sheet P to be printed from the printer unit 300 of the copying machine 1000 (sheet size identification process) (FIG. 14: step S1). Then, the finisher controller 515 moves the sheet stopper 805 as shown in FIG. 3 based on the information on the conveyance direction length L of the sheet (bundle) P, and the needle position 820c from the intermediate position (L / 2) of the sheet bundle conveyance direction. Is moved to a position facing the lower side by −α and waits (FIG. 14: S2). The sheet bundle conveyance direction intermediate position is half L / 2 of the conveyance direction length L of the sheet bundle P stacked on the storage guide 803. Details of the “shift amount α” will be described later.

  The sheet P conveyed into the finisher 500 is guided to the saddle discharge path 523 by the finisher control unit 515 operating the switching member 514 in the middle of the lower discharge path 522 so as to switch the sheet P to the right side in FIG. The saddle stitch bookbinding unit 800 is guided. Then, the sheet is conveyed into the storage guide 803 by the pair of saddle inlet rollers 801 and the intermediate roller 804, hits the sheet stopper 805, and the conveyance is completed. In this way, the sheets P are sequentially stacked with the sheet stopper 805 as a reference (sheet storing operation) (FIG. 14: S3).

  Thereafter, under the control of the finisher control unit 515, the alignment plate pair 815 also aligns the width direction orthogonal to the sheet conveying direction (sheet alignment operation) (FIG. 14: S4). At this time, the sheet stopper 805 waits not on the L / 2 lower side than the staple position 820c (needle binding position) of the stapler 820 but on the L / 2-α lower side as shown in FIG. The stapling process is performed in this state under the control of the finisher control unit 515. For this reason, as shown in FIG. 4, with respect to the sheet bundle P, the sheet stopper P 805 is positioned L / 2−α away from the position L / 2 from the end (sheet center Pc) by α. Stapling is performed (staple processing) (FIG. 14: S6). Whether or not the sheet is the final sheet is determined between step S4 and step S6, and step S3 is repeated until the final sheet is determined. When the final sheet is determined, the process proceeds to step S6.

  Thereafter, as shown in FIG. 5, the finisher control unit 515 lowers the sheet stopper 805, whereby the sheet bundle P is also lowered to the folding position (folding position) (FIG. 14: S7). At this time, as shown in FIGS. 5 and 6, the sheet stopper 805 is positioned L / 2 below the center of the nip of the first folding roller pair 810, that is, the protrusion center 830 c which is the center of the protrusion member 830. The positions of the protruding portion center 830c and the center Pc of the sheet bundle P are aligned. That is, when the sheet bundle P moves to the folding position (folding position), the distance from the sheet stopper 805 to the center (nip) of the first folding roller pair 810 is L / 2.

  At this position, the sheet bundle P is ejected by the ejecting member 830, and is folded and conveyed by the first folding roller pair 810 (protruding / folding operation) (FIG. 14: S8). At this time, as shown in FIG. 7, the position of the folding process of the sheet bundle P and the position of the staple S are shifted by α from immediately after the folding until after the nip of the first folding roller pair 810. In this way, stapling is performed from the sheet stopper 805 to the position of L / 2-α, and the sheet stopper P is bent at the position of L / 2, so that only α is placed at the position of the folding processing position of the sheet bundle P and the staple needle S. Misalignment can occur.

  Thereafter, the sheet bundle P is conveyed and delivered to the second folding roller pair 811 (811a, 811b) (FIG. 14: S9). At this time, since the nip direction of the second folding roller pair 811 is slightly directed to the lower left side (see FIG. 5), the sheet bundle is conveyed by the conveyance guide portion 814 (see FIG. 2) arranged substantially parallel to the nip direction. The tip of P is in a state of facing downward. That is, the sheet bundle P is deflected downward in the conveying direction by the upper guide (conveying guide member) 814a of the conveying guide portion 814, the upper side of the sheet bundle P receives conveying resistance, the upper side is stretched, and the leading end of the sheet bundle is lowered. It will be in the state of facing. For this reason, as shown in FIG. 8A, the sheet bundle P is in a state in which the outside (upper side) is stretched and the inner side (lower side) is slack.

  When a tension state and a sagging state occur in the sheet bundle P in this way, the staple needle S at the folded leading end portion of the sheet bundle that originally deviated from the center as shown in FIG. 8A is shown in FIG. 8B. As shown, it approaches the center.

  In this state, the sheet bundle P enters the third folding roller pair 812 (812a, 812b) and is delivered (FIG. 14: S10). Thereafter, the finisher control unit 515 stops the motor M4 that drives the first folding roller pair 810, the second folding roller pair 811, and the third folding roller pair 812 at a constant speed at the portion of the additional folding roller pair 861, The conveyance of the sheet bundle P is temporarily stopped. At this time, the finisher control unit 515 detects the position of the sheet bundle P by the bundle conveyance position detection sensor 51 (see FIG. 9A) (FIG. 14: S11). The finisher control unit 515 stops the sheet bundle P at the portions of the additional folding roller pair 861 (861a, 861b) and the crushing roller pair 862 (FIG. 14: S12). At this time, as shown in FIG. 9A, the state where the sheet bundle P is stretched and the state where the sheet bundle P is folded and the sagging state remain, but the staple S is located at the center of the distal end. ing.

  Thereafter, the finisher control unit 515 drives the crease press unit driving motor M6 to move the additional folding roller pair 861 and the crushing roller pair 862 in the direction of arrow a in FIG. 18 to perform the additional folding process and the crushing process ( FIG. 14: S13).

  In this way, by performing the additional folding process and the crushing process in a state where the staple staple S is in the central portion of the thickness of the sheet bundle P, the processed product is processed as shown in FIG. 9B. Becomes the center position of the thickness of the sheet bundle P, and is produced as a high-quality saddle-stitched booklet.

  Thereafter, the finisher control unit 515 restarts the bundle conveyance by re-driving the motor M4, and discharges it to the folding tray 840 by the third folding roller pair 812 (812a, 812b) (FIG. 14: S14). Further, it is determined whether or not the discharge of the final bundle has been completed. If it has not been completed, the processing from step S3 is repeated, and if it has been completed, the job (JOB) is ended (FIG. 14: S15).

  Here, the “shift amount α”, which is a feature of the present invention, will be described. 10 and 11, S1 indicates a staple position according to the prior art, and S2 indicates a staple position according to the technique of the present invention.

  When the leading end of the sheet bundle P is turned downward from the state shown in FIG. 10, the upper side is tensioned and the lower side is slack as shown in FIG. Come to the side.

  That is, although it is shifted by k × α when viewed from the outside where the quality is lowered, there is a difference between the inner circumference and the outer circumference by the thickness of the sheet bundle P. In other words, even if the staple S2 is shifted by α, the effect of k × α is obtained when viewed from the outside, and when the booklet is opened, the inner side is shifted only by the α amount. On the other hand, the outside can be greatly moved to the center.

  Since the coefficient k varies depending on the thickness of the sheet bundle P, α is increased as the number of bundles stacked on the storage guide 803 is increased, and α is increased as the sheet thickness is increased. In addition, it is more effective to set the value of the “shift amount α” to be variable. As described above, the shift amount α, which is a predetermined distance, can be set to be different for each number and / or thickness of the sheet bundle P stacked on the storage guide 803. In this case, the shift amount α is shifted by α. The effect of bringing the staple S2 toward the center can be further enhanced.

  In this way, the shift amount α, which is a predetermined distance, can be set to be different for each number of sheets P and thickness of the sheet bundle stacked on the storage guide 803, and a setting method for each number of sheets and thickness is set. They can be used alone or in combination. Thereby, the precision which positions staple staple S2 which shifted | deviated (alpha) to the center side can be improved more.

  In this way, by performing the stapling process below the center Pc of the sheet bundle P by α and performing the folding process by folding the position of the sheet center (center) Pc, the following effects can be obtained. it can. That is, the width of the apparatus is increased by the upper guide 814a that feeds the folded sheet bundle P sent out from the folding processing unit including the first folding roller pair 810 and the protruding member 830 with the folding end portion at the head to the crease press unit 860. Is suppressed. As a result, it is possible to perform the edge processing with the staple needle being in an appropriate position while having an inexpensive configuration. That is, even if the sheet bundle P that is bent and conveyed and is deformed at the leading end of the folded sheet is subjected to additional folding processing and crushing processing, the staple position after processing becomes the center, and the final product This can lead to improved quality.

  In the present embodiment, the upper end guide 814a causes the front end of the sheet bundle to face downward, the sheet bundle P enters the outer side (upper side) due to conveyance resistance from the upper guide 814a, and the inner side (lower side) sag. It becomes a state. For this reason, as shown in FIG. 4, the staple position 820c of the staple S is shifted downward by α relative to the sheet bundle center Pc. However, when the sheet bundle P is guided so that the conveyance guide portion 814 is curved upward from the first folding roller pair 810, the sheet bundle P is slack on the upper side in the bundle conveyance after folding. Will occur. For this reason, by shifting the staple position 820c of the staple needle S upward by α relative to the center (center) Pc of the sheet, the same effect as in the case of the present embodiment can be obtained.

  As described above, by applying the present invention, the finisher 500 including the saddle stitch bookbinding portion 800 having an inexpensive configuration can be obtained without increasing the apparatus width by curving and feeding the sheet bundle P by the upper guide 814a. Can be realized. And the position of the staple S of the saddle stitch bookbinding bundle, which has been shifted to the end of the sheet bundle thickness in the prior art, can be positioned in the center of the bent tip, so that the quality of the final product can be improved.

<Second Embodiment>
Next, a finisher 500 according to the second embodiment of the present invention will be described with reference to FIGS.

  The present embodiment is different from the first embodiment in that there is no second folding roller pair 811, a conveyance guide portion 814, and a third folding roller pair 812, and a conveyance guide portion 891 is provided downstream of the first folding roller pair 810. Is different. This conveyance guide part 891 is comprised from the upper side guide 891a as a conveyance guide member, and the lower side guide 891b, and direction differs from the nip direction of the 1st folding roller pair 810. FIG. In this embodiment, an additional folding roller pair 861 (861a, 861b) and a crushing roller pair 862 are disposed on the downstream side of the conveyance guide portion 891. The conveyance guide portion 891 is formed in a curved shape so as to bend and convey the sheet bundle which is bent and sent out by the nip of the first folding roller pair 810 to the crease press unit 860.

  A control block diagram and a flowchart in this embodiment are the same as those in the first embodiment. Sheets on which images are formed are sequentially received by the sheet stopper 805, and staple processing (stitching processing) is performed by the stapler 820. Then, the process is the same as in the first embodiment until the eye processing for receiving and folding the protruding sheet P by the first folding roller pair 810 is performed. Therefore, those descriptions are omitted.

  In the finisher 500 of the present embodiment, one surface of the sheet bundle P folded and conveyed by the first folding roller pair 810 abuts on the conveyance guide portion 891 and is guided to the lower side of the apparatus. At that time, as described above with reference to FIG. 8B, the sheet bundle P is deflected downward by the upper guide 891a, the upper side of the sheet bundle P receives the conveyance resistance, and the upper side is stretched. As the lower side sags, the leading edge of the sheet bundle faces downward. Therefore, the staple position of the sheet stopper 805 is adjusted so that the staple binding position on the sheet bundle by the stapler 820 approaches the area side (lower surface in FIG. 15) opposite to the area of the sheet bundle that is the one surface (upper surface in FIG. 15). The position was moved in advance by a predetermined distance (shift amount α). As a result, the staple S that has been shifted downward as shown in FIG. 15A moves to the center. In this state, as shown in FIG. 15B, the bundle is conveyed to the additional folding roller pair 861 (861a, 861b) and the crushing roller pair 862, and the bundle conveyance is temporarily stopped.

  Then, by performing the additional folding process and the crushing process from this state, the processed product has the staple needle S positioned at the center of the thickness of the sheet bundle P in the same manner as that shown in FIG. And is produced as a high-quality saddle-stitched booklet.

  As described above, in this embodiment, the same effect as that of the first embodiment can be obtained, and the second folding roller pair 811, the conveyance guide unit 814, and the third folding roller pair 812 can be connected to the conveyance guide unit 891 (891 a and 891 b). The effect is that the configuration is further simplified by the amount replaced with ().

  In the above-described embodiment, the crease process for strengthening the fold of the folded sheet bundle has been described as the end process. However, the squaring process for deforming the folded end part of the folded sheet bundle into a square is applied as the end process. The present invention is also effective.

DESCRIPTION OF SYMBOLS 111,113 ... Image forming part (photosensitive drum, developing device), 500 ... Sheet processing device (finisher), 515 ... Control part (finisher control part), 803 ... Sheet stacking part (storage guide), 805 ... Positioning member (sheet) Stopper), 810, 830 ... Bending processing part (first folding roller pair, protruding member), 814a, 891a ... Conveying guide member (upper guide), 820 ... Needle binding processing part (stapler), 860 ... End processing part (Crease press unit), 1000 ... image forming apparatus (copier), P ... sheet, sheet bundle, α ... predetermined distance (shift amount)

Claims (8)

A sheet stacking unit for sequentially stacking conveyed sheets;
A positioning member that abuts the end of the sheet conveyed to the sheet stacking unit for positioning the sheet bundle stacked on the sheet stacking unit;
A staple binding processing unit that performs a staple binding process on the sheet bundle stacked on the sheet stacking unit,
The positioning member is movable to adjust the staple binding position on the sheet bundle by the staple binding processing unit,
A folding processing unit that folds the sheet bundle that has been stapled by the staple binding unit;
A conveyance guide member that guides the folded sheet bundle while sliding one surface of the folded sheet bundle conveyed from the folding processing section with the folded end as a head;
An end processing unit that performs end processing on the folded end of the folded sheet bundle guided by the conveyance guide member;
When the edge processing is performed by the edge processing unit, the staple binding position is set to a region opposite to the region that becomes the one surface when the sheet bundle stacked on the sheet stacking unit is folded in two. And a control unit that controls the movement of the positioning member so that the staple binding process is performed by moving a predetermined distance in advance.   The folding processing unit includes a pair of folding rollers that sandwich and fold the sheet bundle into two, and a protruding member that pushes the sheet bundle stacked on the sheet stacking unit into the pair of folding rollers. The sheet processing apparatus according to claim 1.   The sheet processing apparatus according to claim 1, wherein the predetermined distance is set according to the number of sheet bundles stacked on the sheet stacking unit.   The sheet processing apparatus according to claim 1, wherein the predetermined distance is set in accordance with a thickness of a sheet bundle stacked on the sheet stacking unit.   The sheet processing apparatus according to claim 1, wherein the predetermined distance is configured such that an operator can arbitrarily set the predetermined distance.   6. The sheet processing apparatus according to claim 1, wherein the edge processing by the edge processing unit is a crease process for reinforcing a fold of a folded sheet bundle.   6. The sheet processing apparatus according to claim 1, wherein the end processing by the end processing unit is a squaring process that deforms a folded end portion of a folded sheet bundle into a square shape. An image forming unit for forming an image on a sheet;
An image forming apparatus comprising: the sheet processing apparatus according to any one of claims 1 to 7, wherein a sheet bundle on which an image is formed by the image forming unit is folded and bound.

Images